ASTM A765/A765M-07(2022)
(Specification)Standard Specification for Carbon Steel and Low-Alloy Steel Pressure-Vessel-Component Forgings with Mandatory Toughness Requirements
Standard Specification for Carbon Steel and Low-Alloy Steel Pressure-Vessel-Component Forgings with Mandatory Toughness Requirements
ABSTRACT
This specification covers heat-treated carbon steel and alloy steel forgings with mandatory toughness requirements. These forgings include tube sheets, covers, channel barrels, integral forged channels, rings, nozzles, flanges, and similar parts. The maximum thickness of forgings produced to this specification is limited only by the capacity of the selected grade to respond to any heat treatment specified and to meet the specified mechanical tests, including impact tests at the specified temperature. Heat treatment shall consist of one of the following treatment options: normalize and temper; double normalize, wherein the second austenitizing temperature is at the same or lower temperature than the first, followed by tempering; quench and temper, with the option of adding a preliminary normalize before austenitizing for quenching in a suitable liquid medium. The forgings shall be subjected to tension and Charpy V-notch impact tests.
SCOPE
1.1 This specification2 covers heat-treated carbon steel and alloy steel forgings with mandatory toughness requirements. These forgings are intended for pressure vessels, feedwater heaters, and similar uses.
1.2 These forgings include tube sheets, covers, channel barrels, integral forged channels, rings, nozzles, flanges, and similar parts.
1.3 All grades are considered weldable under proper conditions.
1.4 The maximum thickness of forgings produced to this specification is limited only by the capacity of the selected grade to respond to any heat treatment specified and to meet the specified mechanical tests, including impact tests at the specified temperature.
1.5 Material supplied to this specification shall conform to the requirements of Specification A788/A788M, which outlines additional ordering information, manufacturing requirements, testing and retesting methods and procedures, marking, certification, product analysis variations, and additional supplementary requirements.
1.6 If the requirements of this specification are in conflict with the requirements of Specification A788/A788M, the requirements of this specification shall prevail.
1.7 The values stated in either inch-pound units or SI [metric] units are to be regarded separately as standard; within the text and tables, the SI units are shown in brackets. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.
1.8 Unless the order specifies the applicable “M” specification designation, the material shall be furnished to the inch-pound units.
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:A765/A765M −07 (Reapproved 2022)
Standard Specification for
Carbon Steel and Low-Alloy Steel Pressure-Vessel-
Component Forgings with Mandatory Toughness
Requirements
This standard is issued under the fixed designationA765/A765M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.8 Unless the order specifies the applicable “M” specifica-
2 tion designation, the material shall be furnished to the inch-
1.1 This specification covers heat-treated carbon steel and
pound units.
alloy steel forgings with mandatory toughness requirements.
1.9 This international standard was developed in accor-
These forgings are intended for pressure vessels, feedwater
dance with internationally recognized principles on standard-
heaters, and similar uses.
ization established in the Decision on Principles for the
1.2 These forgings include tube sheets, covers, channel
Development of International Standards, Guides and Recom-
barrels, integral forged channels, rings, nozzles, flanges, and
mendations issued by the World Trade Organization Technical
similar parts.
Barriers to Trade (TBT) Committee.
1.3 All grades are considered weldable under proper condi-
tions.
2. Referenced Documents
1.4 The maximum thickness of forgings produced to this
2.1 ASTM Standards:
specification is limited only by the capacity of the selected
A275/A275MPracticeforMagneticParticleExaminationof
gradetorespondtoanyheattreatmentspecifiedandtomeetthe
Steel Forgings
specified mechanical tests, including impact tests at the speci-
A370Test Methods and Definitions for Mechanical Testing
fied temperature.
of Steel Products
A388/A388MPractice for Ultrasonic Examination of Steel
1.5 Material supplied to this specification shall conform to
Forgings
the requirements of Specification A788/A788M, which out-
A788/A788MSpecification for Steel Forgings, General Re-
lines additional ordering information, manufacturing
quirements
requirements, testing and retesting methods and procedures,
E112Test Methods for Determining Average Grain Size
marking, certification, product analysis variations, and addi-
E165/E165MPractice for Liquid Penetrant Testing for Gen-
tional supplementary requirements.
eral Industry
1.6 If the requirements of this specification are in conflict
2.2 ASME Standard:
with the requirements of Specification A788/A788M, the
ASMEBoiler and Pressure Vessel Code
requirements of this specification shall prevail.
1.7 The values stated in either inch-pound units or SI
3. Ordering Information
[metric] units are to be regarded separately as standard; within
3.1 In addition to the ordering information requirements of
the text and tables, the SI units are shown in brackets. The
Specification A788/A788M, a detailed sketch or written de-
values stated in each system are not necessarily exact equiva-
scription of the forging and the method of selecting the test
lents; therefore, to ensure conformance with the standard, each
location (see 6.2) should be supplied to the producer, when
system shall be used independently of the other, and values
appropriate areas of significant in-service loading of the
from the two systems shall not be combined.
forging need to be designated.
This specification is under the jurisdiction ofASTM Committee A01 on Steel,
Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee For referenced ASTM standards, visit the ASTM website, www.astm.org, or
A01.06 on Steel Forgings and Billets. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Sept. 1, 2022. Published September 2022. Originally Standards volume information, refer to the standard’s Document Summary page on
approved in 1979. Last previous edition approved in 2017 as A765/ the ASTM website.
A765M–07(2017). DOI: 10.1520/A0765_A0765M-07R22. Available from American Society of Mechanical Engineers (ASME), ASME
For ASME Boiler and Pressure Vessel Code applications, see related Specifi- International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
cation SA–765/SA–765M in Section II of that code. www.asme.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A765/A765M−07 (2022)
TABLE 1 Chemical Requirements
6. Mechanical Requirements
Composition, %
6.1 General Requirements—The forgings shall conform to
Grade I Grade II Grade III Grade IV Grade V
thetensiontestrequirementsofTable2.Theforgingsshallalso
Carbon, max 0.30 0.30 0.20 0.20 0.30
conformtotheimpacttestrequirementsofTable3.Thelargest
Manganese 0.60 to 0.60 to 0.90 max 1.00–1.60 0.60–1.35
obtainable round tension test specimen as specified in Test
1.35 1.35
Phosphorus, 0.020 0.020 0.020 0.020 0.020
Methods and Definitions A370 shall be used. Impact speci-
max
mens shall be CharpyV-notch,TypeA, as inTest Methods and
Sulfur, max 0.020 0.020 0.020 0.020 0.020
DefinitionsA370.Theusageofsubsizeimpactspecimensmust
Silicon 0.15 to 0.15 to 0.15 to 0.15–0.50 0.15–0.35
0.35 0.35 0.35
have prior purchaser approval.
A
Nickel, max 0.50 0.50 3.3 to 3.8 0.50 max 1.0–2.0
6.1.1 When agreed upon between the purchaser and the
Vanadium, max 0.05 0.05 0.05 0.06 0.03
Aluminum, max 0.05 0.05 0.05 0.05 0.05 producer and specified on the order, impact tests may be made
A
Chromium, 0.40 0.40 0.20 0.40 0.30
attemperaturesdifferentfromthoseshowninTable3provided
max
A
the test temperature is at least as low as the intended service
Molybdenum, 0.10 0.10 0.06 0.10 0.12
max
temperatures and the provided impact energy requirements of
Copper, max 0.35 0.35 0.35 0.35 0.35
Table 3 are met. Such forgings shall be suitably marked in
A
Intentional additions of Cr, Mo, and Ni up to the specified maximum are permitted
accordance with 9.1 to identify the test temperature.
to be made to Grades I, II, and IV by the manufacturer.
6.2 Test Location—Test coupons shall be taken so that the
longitudinal axis and mid-length of tension and impact test
specimens shall be positioned in accordance with one of the
3.2 Therequiredimpacttesttemperatureshouldbesupplied
following methods:
ifdifferentthanthetemperaturelistedinTable3,otherwisethe
6.2.1 Method 1—Forgings with 2 in. [50 mm] maximum
impacttestshallbeconductedatthetemperaturelistedinTable
thickness. The specimens shall have their longitudinal axis at
3 for the chosen Grade.
the midthickness or the center of the cross section and with the
3.3 IfahubbedtubesheetistobesuppliedforASMEBoiler
midlength of the specimen at least 2 in. [50 mm] from any
and Pressure Code Application Supplementary Requirement second surface.
S12 of Specification A788/A788M shall be specified.
6.2.2 Method 2—Grade I and Grade II forgings with thick-
nesses greater than 2 in. up to 4 in. [50mm to 100 mm]
3.4 If steel is required to be vacuum degassed, Supplemen-
inclusive,orGradeIIIandIVforgingswiththicknessesgreater
tary Requirement S8 of Specification A788/A788M should be
than 2 in. up to 6 in. [50mm to 150 mm] inclusive. The
specified.
specimens shall have their longitudinal axis at least ⁄4 T of
maximumheat-treatedthicknessfromanysurfaceandwiththe
4. Heat Treatment for Mechanical Properties
midlength of the specimen at least one T from any second
4.1 Heat treatment shall consist of one of the following heat
surface.This is normally referred to as ⁄4 T by T when T is the
treatment options of the manufacturer’s choice.
maximumheat-treatedthickness.Athermalbuffermaybeused
4.1.1 Normalize and temper.
to adhere to the condition in 6.3. Unless otherwise agreed
4.1.2 Double normalize, wherein the second austenitizing
upon, the following limitation for heat-treated thickness shall
temperature is at the same or lower temperature than the first,
apply:
followed by tempering.
Grade in. [mm], min in. [mm], max
4.1.3 Quench and temper, with the option of adding a
I 2 [50] 4 [100]
preliminary normalize before austenitizing for quenching in a
II 2 [50] 4 [100]
suitableliquidmedium.Thetypeofcoolingmediumusedshall III 2 [50] 6 [150]
IV 2 [50] 6 [150]
be reported.
V 2 [50] 6 [150]
4.1.4 Use of an intercritical heat treatment cycle in accor-
(Classes 1 and 2)
dance with Specification A788/A788M in which cooling from
6.2.3 Method 3—For forgings thicker than described in
thefullandpartialaustenitizationstagesmaybedonebyliquid
Method 2 (6.2.2):
quenching or air cooling. The method of cooling and type of
6.2.3.1 Priortoheattreatmenttheforgingshallbemachined
quench medium, if used, shall be reported.
to a purchaser supplied or approved drawing that indicates the
4.1.5 The minimum tempering temperature shall be 1100ºF
locations of significant in-service loading in the finished part.
[590ºC].
The mechanical test specimens shall be located as an integral
part of the forging such that the mid-point of the gauge length
5. Chemical Requirements
ofthetensiontestspecimenandtheareaunderthenotchofthe
5.1 Heat Analysis—The heat analysis obtained from sam-
impact specimens are located no closer than the dimension t
pling in accordance with Specification A788/A788M shall
fromoneheattreatedsurfaceand2tfromanyotherheattreated
comply with Table 1.
surface where t is the dimension from the area of significant
loadingtotheheattreatedsurface,or ⁄4in.[20mm]whichever
5.2 Product Analysis—The purchaser may use the product
analysis provision of Specification A788/A788M to obtain a is the greater.
product analysis from a forging representing each heat or 6.2.4 Method 4—This method shall be limited to forgings
multiple heat. with a rough machined weight of not more than 1000 lb
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